Means for cooling high vacuum rotary pumps



July 15, 1958 R. D. PARMLEY MEANS FOR coouuc HIGH VACUUM ROTARY PUMPS Filed April 18. 1956 2 Sheets-Sheet 1 INLET INVENTOR 1). b wvmjuj ATTORNEYS July 15, 1958 PARMLEY 2,843,313

MEANS FOR COOLING HIGH VACUUM ROTARY PUMPS Filed April 18. 1956 2 Sheets-Sheet 2 *EXHAUST 22 l I 5 A H I 1 1 I, 7 6 INLET 1."

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MEANS Fen cooLING HIGH VACUUM ROTARY PUMPS Ralph D. Parmley, Mendham, N. J., assignor to Leiman Ernst, Inc, Newark, N. L, a corporation of New Jersey Application April 18, 1956, Serial No. 579,088

2 Claims. (Cl. 230--207) My invention is directed to novel means for cooling high vacuum rotary pumps.

The object of my invention is to cool the hot lubrieating oil after it has left the oil separator of the vacuum pump and has been returned to the oil reservoir and is being drawn again into the pump; thereby insuring a suificient lubrication of the pump to prevent it from overheating.

A practical means for carrying out my invention is represented in the accompanying drawings.

Fig. 1 represents the high vacuum rotary pump in side elevation.

Pig. 2 represents a rear elevation of the same.

Fig. 3 represents an enlarged partial section taken in the plane of the line IIIIII of Fig. 2.

The lubricating oil reservoir is denoted by 1 and it is housed in a suitable base 2. This reservoir may be provided with a filler pipe 3 to keep the oil at the desired level.

The high vacuum rotary pump 4 is shown as provided with a cooled oil inlet 5, an air inlet 6 and an oil impregnated air discharge outlet 7, The shaft 8 of this pump 4 is provided with a pulley 9, operatively connected by a belt 10 to a pulley 11 on the shaft 12 of the rotary electric motor 13. Both the motor and the pump are shown as mounted on the oil reservoir base 2.

The usual oil separator 14 which surmounts the pump 4 has an air exhaust port 15 and an inlet 16 which is connected to the pump discharge outlet 7. The separated oil passes downwards through the drip pipe 17 which leads downwards from the separator 14 into the oil reservoir 1 above the oil level therein.

The unit for cooling the oil as it is drawn from the reservoir 1 to the pump 4 comprises the following elements; a radiator 18 (which is mounted on the oil reservoir base 2), and its cooling fan 19 which is fixed to the motor shaft 12.

The vacuum pump 4 draws the hot oil through the pipe 20, which leads from the reservoir 1 below its oil level to the bottom of the radiator 18 to supply the oil thereto. Another pipe 21 leads from the top of the radiator 18, to the interior of the vacuum pump 4 nited States Patent 2,843,313 Patented July 15, 1958 ice (preferably through a sight feed 22) to supply the cooled oil to the pump.

It will be seen that the hot lubricating oil which has been separated from the air by the separator 14 is returned by gravity flow to the reservoir above the oil level therein. The hot oil is then drawn by the suction of the vacuum pump, through the cooling unit back to the pump. This flow of cooled oil is suflicient to keep the pump cool enough to prevent damage thereto by overheating. Also by this cooling of the oil, its viscosity is kept at a point where it provides a better lubricating film and thereby a better seal for the vacuum. Also, keeping the pump cool increases its volumetric elticiency and materially lengthens the life of the pump and enables it to pull a higher vacuum.

What I claim is:

1. In combination, a suitable base, a lubricating oil reservoir housed therein and provided with a filler pipe to keep the oil at the desired level, a high vacuum rotary pump mounted on said base and having a cooled oil inlet, an air inlet and an oil impregnated air discharge outlet, an oil separator surmounting the pump and having an air exhaust port, an inlet connected to the air discharge outlet of the pump, and a drip pipe for the separated oil leading to the reservoir above its oil level, and an oil cooling unit also mounted on said base provided with a pipe leading to the reservoir below its oil level and another pipe leading to the cooled oil inlet of the pump, said pump being operable to draw the oil from the reservoir through the oil cooling unit to said pump.

2. In combination, a suitable base, a lubricating oil reservoir housed therein and provided with a filler pipe to keep the oil at the desired level, a high vacuum rotary pump mounted on said base and having a cooled oil inlet, an air inlet and an oil impregnated air discharge outlet, an oil separator surmounting the pump and having an air exhaust, an inlet connected to the air discharge outlet of the pump, and a drip pipe for the separated oil leading to the reservoir above its oil level, an oil cooling unit also mounted on said base and including a radiator and its cooling fan, said radiator being provided with a pipe leading to the reservoir below its oil level and another pipe leading to the cooled oil inlet to the pump, and a rotary electric motor having a belt and pulley driving connection with the fan and the said pump, to cause the pump to draw the oil from the reservoir through the radiator into the pump.

References Cited in the file of this patent UNITED STATES PATENTS 1,967,035 Lipman July 17, 1934 2,178,425 Johnson Oct. 31, 1939 2,289,441 Valley et a1. July 14, 1942 2,455,297 Curtis et al. Nov. 30, 1948 2,540,714 Curtis et a1. Feb. 6, 1951 

